console.log('script start')
    async function async1() {
      await async2()  //加了await 的代码会立即执行，且后面的代码会被阻塞，会导致后面的代码去到下一次的为任务队列中去
      console.log('async1 end')//v8正在违反规定await 后面的代码提上一个循环
    }
    async function async2() {
      console.log('async2 end')
    }
    async1()
    setTimeout(function () {
      console.log('setTimeout')
    }, 0)
    new Promise(resolve => {
      console.log('Promise') 
      resolve()
    })
      .then(function () {
        console.log('promise1')
      })
      .then(function () {
        console.log('promise2')
      })
    console.log('script end')
//script start
//async2 end
// promise
//script end 自此为微任务循环
//async1 end -----提上了一个循环
//promise1
//promise2
//setTimeout
